Stamps are printed on paper, though most collectors wish it were granite. The quality of perfection demanded by collectors far exceeds the bounds of reality. Paper, as it ages, becomes brittle. Any 100-year-old stamp has probably been owned by fifteen people and handled hundreds of times. It may well have faults. Faults refers to flaws in the paper.
There are three main types of faults. Thins are areas of the paper that have become scraped away. These usually occur on the back of the stamp, but when they occur on the front they are called “face scrapes.” Thins can occur for a variety of reasons, but most predominant is a stamp being stuck down and then torn away, leaving some paper on the surface that the stamp was stuck to. Furthermore, in the old days, collectors would often peel loosely stuck stamps off envelopes, damaging them, but these early collectors cherished the design and cared little about the paper they were printed on. Creases are bends in the paper that break the fibers in the paper. Often they are caused by careless handling, such as getting caught in a closing album. But many creases were caused by the original postal users. In the early stamp period, stamp booklets and coils, which make it so easy for postal users to carry their stamps about, did not exit. A woman would simply throw some stamps into her purse, or a man drop a few into his pocket, until such time as they were needed.
Creases also were caused as a result of the postal laws that existed in many countries. In the early period, in some countries letters were rated by the umbers of sheets of paper used, not by weight, so people used folded letter sheets. A folded letter sheet is a large piece of paper which is written on and then folded so the outside is blank for an address and a stamp. When a business got a letter like this, it was convenient to refold the letter from its side for filing; often the stamp was creased in the process.
A third, most serious, fault is a tear. Tears can mean anything from a millimeter or two to an entire portion o the stamp missing. Significant tears, such as an entire corner missing, generally are considered a fault of such magnitude as to make the stamp worthless. As a general rule, small thins, small creases, and tears of 1 millimeter or less decrease the value of an otherwise perfect stamp by about one-half. More significant tears, creases, and thins generally decrease the value of the stamp according to the significance of the fault.
It is one thing to know that stamp values are affected by faults and quite another thing to develop the skills to determine if a stamp does have a fault. Many faults can be spotted by the use of a good strong light. If you hold the tamp up to the light (incandescent, or fluorescent, works best0, the thin will show up lighter than the surrounding areas. This is because the paper acts as a medium through which the light must travel. So where the paper is thinned, there will be more light passing through and the paper will consequently appear lighter. A crease shows up as a light line and a tear shows up as a break in the paper.
To determine faults, most philatelists use a watermark tray. The tray is a small, black plastic or glass dish, into which commercially prepared watermark fluid is poured. It was originally developed for watermarking stamps, and proved so efficient that advanced philatelists then expanded its use to include searching for altered stamps. To watermark a stamp—that is, to determine which watermark the stamp has—the collector places the stamp face down in the tray filled with the watermark fluid. The pattern of the watermark will show up darkly because, where the watermark is, the paper is thinner. Thins, which show up as dark patches not part of the watermark, can also be seen. Creases show up as thin dark lines, and tears as somewhat thicker dark lines. The watermark fluid will not damage the gum of an unused stamp, though collectors should not place photo-engraved stamps or stamps printed on chalky paper into the watermark fluid. Neither type of printing fixes the ink, and there is a danger of the design fading or spreading. A special watermark fluid is made for these stamps.
The use of the tray is what separates philatelic novices from the experts. The tray is philately’s X-ray machine, and the analogy is precise. It is difficult to use the tray properly, but one who is adept in using it can discern the most subtle characteristics of a stamp. Because stamp values are so utterly dependent on condition, unscrupulous philatelists have for years attempted to alter the quality of their stamps. There is nothing unethical about repairing a stamp if it is to be sold as repaired. However, very often repairs are made to make a stamp appear perfect so that it can be sold for a higher price. Such alteration is exceedingly difficult to tell even under magnification, but it shows up quite readily in the tray.
One of the ways a stamp can be repaired is by what is called “filling” a thin. A thin can be filled by using a form of paper glue or a solution made with egg white. The solution is painted onto the thin, allowed to dry, then lightly sanded so that it fits into the contours of the stamp paper. This repair will make a stamp that is held up to the light appear as if it has not been thinned. But not so in the tray! Though the filled spot is the same thickness as the paper around it, it is not the same consistency. Since it is not the same broad weave as the paper around it but rather a patch, it shows up in the tray as much denser, that is, whiter, against the black background. Filled thins can be as small as a pinpoint or as large as most of the stamp.
It is recommended that collectors who are graduating from novice to more advanced status keep their old collections of cheap stamps, which offer a wealth of perfect and marginally defective stamps on which to learn the skills of the tray. No one would fill the thin of a stamp worth 3 cents, so you can see a good percentage of unrepaired stamps in this group. You can learn what creases and thins look like in the tray, along with how the weave of paper should look on a perfect stamp.
Creases can be repaired, too. This is generally done by ironing them out, using an ordinary iron but first placing the stamp under a cloth so that it doesn’t burn. The stamp is usually moistened and the heat spreads the fibers of the paper, causing the crease to become invisible—except in the tray. There it shows as a thick dull line. Tears can be closed using liquid cement; margins can be added, in fact, the amount of repairs and alterations possible to a stamp are myriad. We have just touched on the use of the tray. Most dealers and stamp clubs will give you further instruction. Several universities, including Penn State in State College, Pennsylvania, and Temple University in Philadelphia, gives courses in philately that include sections on how to use a tray. If you assumed that stamps were as they appeared, and never used a tray, you would be correct about 90 percent of the time. But when you are spending your money, it pays to be right 100 percent of the time. Reputable dealers will allow the use of the tray at their office; or if time and space do not permit this (at stamp shows, for example), they will allow the return for full refund of anything that, when trayed at home, does not meet the grade it was sold as having. Be aware, though, that virtually no items costing less than $10 have been repaired, and requesting a tray to view such an item is the surest way of branding yourself a nuisance.